Apparatus for drying liquid-impregnated fibrous or spongy materials, especially sugar-cane bagasse

ABSTRACT

Fibrous material is passed between a perforated cylinder and a pressing cylinder, the first being provided with means adapted to collect expressed liquid and to remove it preferably from at least one of the ends of the cylinder. The perforated cylinder is of larger diameter and the pressing cylinder is subject to the action of an adjustable pressing means, and is arranged above the perforated cylinder and laterally of the latter. The shaft of the pressing cylinder is displacable in slides and subject to an action tending to bring it towards the perforated cylinder.

United States Patent 11 1 Barre 1 Oct. 2, 1973 [54] APPARATUS FOR DRYING 1,845,140 2/1932 Farrel, Jr. 100 176 L10UDJMPREGNATED R U 1,482,005 1/1924 Giordano.... 100/176 SPONGY MATERIALS, ESPECIALLY 1,539,502 5/1925 Okrassa 100/169-X SUGAR-CANE BAGASSE FOREIGN PATENTS 0R APPLICATlONS [75] Inventor; Marcel Jean Charles Barre, 512,528 2/1955 ltaly 100/121 p j'rh il France 39,516 1915 Norway 100 169 1 393,835 6/1933 Great Britain 100/121 Assignee: Societe Sucriere De LAtlantique (Engineering), Paris, France Filed: Dec. 2, 1970 Appl. No.: 94,345

Foreign Application Priority Data Dec. 5, 1969 References Cited UNITED STATES PATENTS France 6942223 3 1901 Logemanml 121 x 50,158 9/1865 P00161131 100 121 ux Primary Examiner-Edward L. Roberts Att0rneyW.aters, Roditi, Schwartz-& Nissen [57] ABSTRACT adjustable pressing means, and is arranged above the perforated cylinder and laterally of the latter. The shaft of the pressing cylinder is displacable in slides and subject to an action tending to bring it towards the perforated cylinder.

4 Claims, 3 DrawingFigures APPARATUS FOR DRYING LIQUlD-IMPREGNATED FIBROUS OR SPONGY MATERIALS, ESPECIALLY SUGAR-CANE BAGASSE The invention relates to apparatus for drying fibrous materials of the sugar cane bagasse type, especially for the treatment of this bagasse at the outlet of a cane sugar extraction installation.

It is known that the treatment of the bagasse has the object of extracting a certain percentage of slightly sweetened juice, entrained after the extraction operation in the impregnated fibrous material. It is hence necessary to perform a draining step which enables this extraction to be done, while the fibrous material proper is removed.

In known methods the bagasse, at the outlet of the extraction installation, is first distributed by a heavy and cumbrous apparatus, e.g., a rotary scraper, or by a set of equally cumbersome screws. Then this bagasse is led by conveyors on to a first mill with three cylinders, called a repressing mill, which has the task of extracting a portion of the water with which the bagasse is charged. 1

But the mill, used for half a century in cane sugar works, is maladapted for the pressing of hot bagasse containing more than 80 percent water. It consumes much energy and requires much maintenance. Pressing screws have also been tried but they have the same drawbacks. I To overcome these various disadvantages, according to the invention, there is provided apparatus by which fibrous material to be treated is caused to pass by force betweentwo cylinders one of which is perforated, so that the liquid is caused to penetrate into the latter, where, by suitable means, it is collected-preferably at one end of this cylinder, while the dried fibers themselves are removed, after passage between the two cylinders.

By proceding in this manner, only a single apparatus is needed instead of two successive apparatuses as in previous known methods. There is as a result a gain of energy, less bulk and reduced maintenance.

An advantageous embodiment consists in having recourse to an apparatus with two substantially horizontal cylinders, one being of smaller diameter and arranged above a perforated extractor cylinder of larger diameter, and laterally thereof, said perforated cylinder comprising means thereinside to collect the liquid and discharge it at least at one of its ends.

The invention comprises, apart from these features, certain other features, which are preferably used at the same time and which will be more explicitly considered below.

It will, in any case, be well understood by means of thedetailed description which follows, as well the accompanying drawings, that the embodiments of the apparatus according to the invention an given of course merely by way of non-limiting example.

In the drawing:

FIG. 1 is a transverse cross-sectional view of one embodiment according to the invention for the treatment of sugar cane bagasse;

FIG. 2 is a longitudinal crosssectional view thereof; and

FIG. 3 is a transverse cross-sectional view of another embodiment.

According to the invention, in order to treat, for example, bagasse provided from a sugar cane extraction installation, to extract the juice from it, the procedure is as follows.

The bagasse is made pass between at least two cylinders, arranged side by side and leaving a certain space into which the bagasse is forced to pass the two cylinders rotating for this purpose in reverse sensese, at least one of these cylinders being perforated, and being provided with means adapted to receive the liquid and to conduct it towards one of its ends.

Advantagenously, the distance between the cylinders is adjustable and hence the cross-section for the pase sage of the bagasse can be regulated, this against the action, also possibly adjustable, of elastic or other means, tending to urge the cylinders together and consequently to exert a gripping action on the bagasse.

For the application of these features, recourse may be had especially to the embodiment illustrated in FIGS. 1 and 2.

According to this embodiment, for which it is assumed that the cylinders are horizontal (although they could be slightly inclined), recourse is had to an extracting principal cylinder 1 of largest diameter, pierced with holes 3, with which a non-perforated pressing cylinder 2 is made to cooperate, of smaller .di-

ameter with its shaft 12 at a level a little higher than that of the .shaft 13 of cylinder 1 and laterally thereof.

The extractor cylinder 1 is forexample driven by gears 14, 15 from a shaft 16 actuated by a motor 17,

The pressing cylinder 2, driven itself by another motor 18, is displacable for example by means of slid ers 19 (FIG. I) movable in slides 20, and its shaft 12 is subject to the action of a force tending to urge it closer to the extractor cylinder. This force is developed for example by a counterweight 21 ssupended on a cable 22 passing over pulleys 23, 24, any other system, of course, being conceivable. Recourse could especially be had to jacks, springs, etc.

This assembly is completed by a hopper 9 which brings the bagasse above the cylinders, and by projections or blades 10 provided on the outside of the cylinders for driving said bagasse between the cylinders. Conveyer means, for example a belt 11, is in addition provided below the cylindersifor the removal ,of the dried fibers.

Now as regards the means for collecting the extracted liquid and to carry it towards toone end of the extractor cylinder 1, this can be constituted by men .bers such as gutters .or the like, adapted to channel the said liquid suitably (if necessary, as indicated above, a certain slant of the cylinders could assist this extrac! tion).

These collector means can be, either fixed to the wall of .the extractor cylinder thereby turning with thelatter, or on the contrary be non-rotary.

Said means, according to the embodiment shown in FIG. 1, consists of 25 provided axially between the wall of the cylinder 3 and a central .cone 26 whose apex is directed towards the outlet of the liquid. This outlet is constituted by a spout .8, anyother means being .1usable.

As regards also the latter means, another arrangement is shown in (FIG. 3) and consists in providinginside the cylinder I, assumed to turn by suitable ,befarings on the shaft 13 assumed non-rotary, an inclined partition 27 (shown diagrammatically at MN in :FIG. .3,

and intended to replace the extractor system 25, 26

provided in the embodiment of FIG. 1) borne by the shaft 13. This partition 27 collects at its upper part at M the juice extracted from the bagasse and allows it to flow towards the lower part at N. At this spot, the juice is led to traverse the cylinder again, through the perforations 3, and is collected in a suitable gutter.

Thus there is provided an assembly such that the bagasse is introduced between cylinders whose separation and speed of rotation are selected so as to distribute the product while making it undergo compression at the time of its passage between the cylinders. In this way a large portion of the liquid passes hrough the holes of the perforated cylinder, to be received in the receiver means and to be removed towares the outlet gutter, while the dried fibers are themseleves removed by the conveyor or the like. It is understood that, if necessary, two successive trains of rollers could be provided.

Such an assembly has numerous advantages with respect to already existing installations of the type concerned, especially:

that of enabling recourse to be had to a single apparatus, the one or more known methods requiring recourse to several successive units of apparatus, that of resulting in. a low cost price.

As is self-evident, and as also emerges already from the preceding description, the invention is in no way limited to its application, nor to its various parts, which have been more especially considered; it embrases, on the contrarty, all variations which fall within the scope of the appended claims.

I claim:

1. Apparatus for drying fibrous material of the sugar cane bagasse type, comprising in combination:

an axially rotatable perforated cylinder,

an axially rotatable pressing cylinder of smaller diameter than said perforated cylinder and arranged above the perforated cylinder and having an axis substantially parallel to said perforated cylinder,

means for urging said pressing cylinder toward said perforated cylinder,

means for feeding fibrous materials to the cylinders,

separare motors for respectively rotating said cylinders in order to cause said fibrous materials to pass between and be pressed in a space between cylinders,

external projections on the cylinders adapted to exert a mechanical pressure on the fibrous materials, the combined action of the external projections and separate driving motors being effective by control of the speed of rotating of the cylinders to distribute th fibrous material between the cylinders while producing compression of the fibrous material to cause liquid removal from the fibrous materal and resultant passage of the liquid into the perforated cylinder, and

means for removing the liquid from the perforated cylibder.

2. Apparatus according to claim 1 comprising a mechanical, guide system supporting the pressing cylinder and allowing the latter to be displaced under the action of the pressure force developed between the cylinders upon passage of the fibrous material between said-cylinders.

3. Apparatus according to claim 1 wherein the means for removing liquid includes a liquid collector at least at one end of the perforated cylinder.

4. Apparatus according to claim 1 wherein the pressing cylinder is arranged laterally of the perforated cylinder. 

1. Apparatus for drying fibrous material of the sugar cane bagasse type, comprising in combination: an axially rotatable perforated cylinder, an axially rotatable pressing cylinder of smaller diameter than said perforated cylinder and arranged above the perforated cylinder and having an axis substantially parallel to said perforated cylinder, means for urging said pressing cylinder toward said perforated cylinder, means for feeding fibrous materials to the cylinders, separare motors for respectively rotating said cylinders in order to cause said fibrous materials to pass between and be pressed in a space between cylinders, external projections on the cylinders adapted to exert a mechanical pressure on the fibrous materials, the combined action of the external projections and separate driving motors being effective by control of the speed of rotating of the cylinders to distribute th fibrous material between the cylinders while producing compression of the fibrous material to cause liquid removal from the fibrous materal and resultant passage of the liquid into the perforated cylinder, and means for removing the liquid from the perforated cylibder.
 2. Apparatus according to claim 1 comprising a mechanical guide system supporting the pressing cylinder and allowing the latter to be displaced under the action of the pressure force developed between the cylinders upon passage of the fibrous material between said cylinders.
 3. Apparatus according to claim 1 wherein the means for removing liquid includes a liquid collector at least at one end of the perforated cylinder.
 4. Apparatus according to claim 1 wherein the pressing cylinder is arranged laterally of the perforated cylinder. 